Pre-configure image to do RotorS Gazebo simulation

This starts with the Ubuntu Xenial Lunar tag of ROS base image, and follows the install steps from RotorS

Quickstart

Specify your own VNC password for the container:

    clone https://github.com/shrmpy/rotors.git && cd rotors && \
    docker build --build-arg VNC_PASSWORD=MyPassGoesHere --network=host --add-host=$HOSTNAME:127.0.0.1 -t rotors .

Run your container (e.g., with a mounted subdir to save screenshots):

    mkdir Pictures && docker run --network=host --rm -ti -v $(pwd)/Pictures:/home/gopher/.gazebo/pictures rotors

Connect with VNC viewer, and enter the VNC password from the step above when prompted:

    vncviewer vnc://localhost:5900

Once inside the container, start Gazebo:

    Shift-Alt-Enter                           #(hot-key st term)
    $ bash                                    #(bash shell to dot-source)
    $ roslaunch rotors_gazebo mav_hovering_example.launch